The present invention relates to an omnidirectional vehicle that exhibits the so-called holonomic moving characteristics. More specifically, the present invention relates to an omnidirectional vehicle that is able to immediately move or start to turn from an arbitrary vehicle position to a desired direction without a waiting time for setup for preparing, for example, the change of orientation of the wheels thereof, in changing the turning speed or moving direction, or in changing from the stop condition to movement or in starting to turn the direction. The vehicle also may change the moving direction or turning direction even during the middle of moving operation. The present invention relates also to a method of controlling the omnidirectional vehicle that exhibits the holonomic moving characteristics.
The omnidirectional vehicle is a vehicle that is capable of controlling three situations freely, i.e. moving or travelling velocity in a moving direction, traveling or travelling velocity perpendicular to the traveling direction, and angular velocity around a vertical axis of the vehicle. Many inventions have been disclosed on the omnidirectional vehicle. The omnidirectional vehicles may be classified into a non-holonomic vehicle and a holonomic vehicle.
It is necessary for the non-holonomic vehicle to conduct a setup operation and a setup time for changing the setup of a part of the mechanisms in the vehicle, such as changing the orientation of each wheel in changing the traveling direction of the vehicle or in shifting to a turning motion. This vehicle has a mechanism that has two free situations. The non-holonomic vehicle is unable to simultaneously control the three free situations of the vehicle independently. The non-holonomic vehicle sets two of the three free situations one by one, and finally, controls the three free situations of the vehicle.
Therefore, the non-holonomic vehicle is unable to trace a trajectory having a right angle corner without spending a setup time. In tracing a right angle corner, the non-holonomic vehicle will trace a circular trajectory if the vehicle does not wait for the setup time. Or, it is necessary for the non-holonomic vehicle to stop at the right angle corner and to resume traveling after the setup time has elapsed. An example of the non-holonomic vehicle is the omnidirectional vehicle that steers all the wheels thereof.
On the other hand, the holonomic vehicle is able to start moving and turning in all the directions instantaneously to an arbitrary orientation from an arbitrary position without changing the setup of the internal mechanisms thereof. The specific feature of the holonomic vehicle is that the holonomic vehicle is capable of simultaneously controlling the three free situations independently. Examples of the holonomic vehicle include an omnidirectional vehicle that employs a spherical wheel, and an omnidirectional vehicle that employs a special wheel mechanism including a large wheel and many rollers arranged around the large wheel and capable of freely rolling laterally.
The holonomic omnidirectional vehicle disclosed by the present inventor in Japanese Patent Unexamined Publication No. 9-164968 includes two or more driving wheel mechanisms, each including an actuator for driving a caster-type wheel and an actuator for driving the steering shaft of the caster-type wheel, to obtain an omnidirectional movement with the three free situations. The wheel mechanism disclosed in the above identified patent publication can use ordinary tires, such as gum tires and pneumatic tires, and obtain a smooth and swift omnidirectional movements.
Since the wheel mechanism disclosed in Japanese Patent Unexamined Publication No. 9-164968 includes the steering shaft that continuously rotates endlessly, the actuator for driving the wheel shaft and the actuator for driving the steering shaft are mounted on a body of the vehicle due to the ease of wiring. Since the rotational movements of the actuators are transmitted via rotating mechanisms such as gears, velocity interference occurs between the actuators.
More in detail, even when the actuator for driving the steering shaft is operated to change the orientation of the wheel while the actuator for driving the wheel is stopped, both the steering shaft and the wheel rotate. In contrast, when the actuator for driving the wheel is operated while the actuator for driving the steering shaft is stopped, only the wheel rotates. Thus, unidirectional velocity interference occurs from the actuator for driving the steering shaft to the actuator for driving the wheel.
To remove the velocity interference described above, it is necessary to conduct a motion control by adding in advance a predetermined rate of the rotating velocity of the steering shaft to the actuator for driving the wheel. In other words, it is necessary to employ an actuator that rotates faster than the maximum rotation frequency necessary only for driving the wheel.
Moreover, it is necessary for the actuator of the steering shaft to generate torque high enough to sustain the torque transmitted to the wheel irrespective of whether the steering shaft is rotating or not, since the torque for driving the wheel acts on the wheel via a fulcrum, that is a certain part, e.g. a gear, of the transmission mechanism of the steering shaft. This means that the torque is exerted suddenly to the steering shaft while the vehicle is accelerating or decelerating or while the vehicle is climbing up or down a step. The torque is nothing but an external turbulence to the actuator for driving the steering shaft.
When an error occurs in the rotating velocity of the steering shaft by the torque from the actuator for driving the wheel, the vehicle deviates from the intended course, further causing a running error of the vehicle. This running error causes a serious problem on the omnidirectional vehicle.
Japanese Patent Unexamined Publication No. 9-164968 also discloses an omnidirectional vehicle including a driving unit having a caster formed of two wheels and an actuator for turning the body of the vehicle. This omnidirectional vehicle controls the translational movement and the rotational movement thereof by controlling three actuators for driving two wheels and for driving the steering shaft of the driving unit. The omnidirectional vehicle avoids the over-restricted state (vehicle is controlled by the actuators more than the number of the actuators for the freedom situations) of the vehicle that employs a plurality of singlewheel-type casters.
Since the actuator for driving the steering shaft is mounted on the driving unit including a caster formed of two wheels, it is necessary to drive the body of the vehicle in the direction opposite to the rotating direction of the driving unit to compensate the orientation change of the driving unit even when the vehicle is not turning, i.e. even when the vehicle is executing a simple translational movement. Therefore, it is necessary for the control calculation in the actuator for controlling the turning of the vehicle to take into account the movements of the vehicle in the direction of the translational movement. This requirement complicates the control system and it becomes necessary to mount an actuator with an extremely high capacity for turning the body of the vehicle.
In short, the interference between a plurality of actuators for driving the vehicle impairs the traveling or moving precision of the vehicle, complicates the control system and increases the capacities of the actuators.
The foregoing problems will be described more in detail below with reference to FIGS. 19 and 20. FIG. 19 is a side view of a conventional caster-type driving wheel mechanism. FIG. 20 is a plan view of the conventional caster-type driving wheel mechanism. The caster-type driving wheel mechanism shown in FIGS. 19 and 20 is a modification of the driving wheel mechanism according to an embodiment disclosed in Japanese Patent Unexamined Publication No. 9-164968.
Referring now to these figures, a bearing 2 rotatably supports a steering shaft 13 around a vertical axis of a body 1 of the vehicle. The steering shaft 13 includes a rotor plate 3. A driving wheel 5 is axially supported by a supporter 4 fixed to the rotor plate 3. The driving wheel 5 is positioned at a location spaced apart for an offset distance s from the center of the rotating axis of the steering shaft 13 in the rolling direction of the driving wheel 5. A motor 10 for driving the steering shaft and a motor 20 for driving the shaft of the driving wheel are mounted on the body 1 of the vehicle and fixed thereto. The motor 10 rotates the steering shaft 13 via a gear 11 on the shaft of the motor 10 and a gear 12 on the steering shaft 13. The motor 20 rotates the driving wheel 5 via a gear 21 on the shaft of the motor 20, spur gears 22, 23, 24, and bevel gears 25, 26.
The driving wheel disclosed in Japanese Patent Unexamined Publication No. 9-164968 generates, as shown in FIG. 21, a velocity in an arbitrary direction in the horizontal plane at the center of the steering shaft, i.e. the center of the rotor plate 3 mounted on the steering shaft 13. That is, the rotation of the driving wheel 5 generates a velocity Vw in the rolling direction thereof. The angular velocity xcfx89s of the circular motion around the ground contact point of the driving wheel 5 caused by the rotation of the steering shaft 13 generates a velocity Vs in the direction perpendicular to the rolling direction of the driving wheel 13. As a result of synthesizing the velocities perpendicular to each other, a velocity V with an arbitrary magnitude in an arbitrary direction is generated at the center of the steering shaft.
When the driving wheel 5 is driven by the motor 20 mounted on the rotor plate 3, the velocity components VS and Vw are controlled independently by the motors 10 and 20, respectively. In the actual wheel design, however, it is required for the steering shaft to continuously rotate multiple times. In most cases, both the motor 20 for driving the shaft of the driving wheel 5 and the motor 10 for driving the steering shaft 13 are mounted on the body of the vehicle due to the wirings that meet the requirement described above. When both the motors 10 and 20 are mounted on the body of the vehicle, the velocity of the motor 10 interferes with the velocity of the motor 20. The interference will be described in detail below.
When the motor 10 is driven to rotate the rotor plate 3 counterclockwise in the plane of a sheet as shown in FIG. 22, the wheel 5 rotates certain degrees of angle by the action of the motor 10 though the motor 20 is not rotating. This corresponds to the state, wherein the gear 23 as well as the motor 20, the gear 21 and the gear 22 are not moving with respect to the body 1 of the vehicle. In other words, the gear 23, the motor 20, the gear 21 and the gear 22 are fixed to the plane of the sheet in FIG. 22.
As the rotor plate 3 rotates, the gear 24 mounted on and fixed to the rotor plate 3 rotates around the gear 23 like a planetary gear. As a result, the gear 24 rotates certain degrees of angle with respect to the rotor plate 3, and the driving wheel 5 rotates certain degrees of angle corresponding the rotation angle of the gear 24. This phenomenon occurs even when the motor 20 for driving the shaft of the driving wheel is rotating. A certain rate of the rotation of the rotor plate 3 is added to the rotation of the driving wheel.
The ratio of the rotation angle of the driving wheel 5 and the rotation angle of the rotor plate 3 takes a certain value determined by the reduction gear ratio of the spur gears 23, 24 and the bevel gears 25, 26. Therefore, the influence of the foregoing velocity interference may be removed by compensating the rotation of the driving wheel 5 caused by the rotation of the rotor plate 3. The rotation of the driving wheel 5 caused by the rotation of the rotor plate 3 is compensated by adding in advance a certain rate of the reference velocity value fed to the motor 10 for driving the steering shaft to the reference velocity value fed to the motor 20 for driving the shaft of the driving wheel.
The countermeasures described above for avoiding the velocity interference are indispensable for the omnidirectional vehicle disclosed in Japanese Patent Unexamined Publication No. 9-164968 to execute the operation as shown in FIG. 21. Therefore, it is necessary for the motor 20 for driving the shaft of the driving wheel 5 to rotate faster than the maximum rotation frequency necessary solely for driving the shaft of the driving wheel, and it is necessary for the motor 20 to have capacity more than necessity.
When a part of the driving wheel 5 contacts the edge of a step while the driving wheel 5 is climbing the step, the motor 20 for driving the shaft of the driving wheel 5 generates large torque to climb up the step. At this moment, however, the driving wheel 5 is locked momentarily and stops rotation until torque large enough to push up the vehicle is transmitted. The torque transmitted to the driving wheel 5 acts on the rotor plate 3 via the spur gears 23 and 24 to rotate the rotor plate 3 and is transmitted further to the motor 10. As a result, an angle error occurs on the rotor plate 3 or, in the worst case, the motor 10 for driving the steering shaft is forced to rotate by the motor 20 for driving the shaft of the driving wheel.
FIG. 23 is a plan view for schematically showing an omnidirectional vehicle according to another embodiment disclosed in Japanese Patent Unexamined Publication No. 9-164968. Referring now to FIG. 23, the omnidirectional vehicle that employs a driving unit including a caster of double-wheel-type facilitates holonomic omnidirectional traveling by three actuators. A motor 150 for driving the steering shaft mounted on a driving unit 55 rotates a body 1 of the vehicle around the driving unit 55. FIG. 24 shows top plan views of the holonomic omnidirectional vehicle of FIG. 23 for explaining the movements thereof. In FIG. 24, the vehicle executes a translational movement in the lateral direction from a state where the driving unit 55 and the body 1 displace from each other by 90 degrees.
Although it is not necessary for the body 1 of the vehicle to change the orientation thereof, the posture of the body 1 changes greatly, since the driving unit 55 operates in the same manner as an ordinary caster. For compensating the influence of the rotation of the driving unit 55, the motor 150 for driving the steering shaft should rotate the body 1 of the vehicle in the opposite direction to keep the body 1 at a certain orientation.
Due to the reason described above, it is required for the motor 150 to generate a maximum velocity that considers the rotation of the driving unit 55, by adding the maximum turning velocity of the driving unit 55 to the maximum turning velocity of the body 1. Since it is necessary to turn the entire driving unit 55, a large driving energy is required. In a vehicle powered by a battery, large electric power is consumed and the running time per one electrification operation is shortened.
In view of the foregoing, it is an object of the invention to provide an omnidirectional vehicle that obviates the foregoing problems.
It is another object of the invention to provide an omnidirectional vehicle as stated above, which can remove the influence of the velocity interference between the actuators for driving the vehicle, simplifies the control system, and minimizes the capacities of the motors for driving the shaft of the driving wheel and for driving the steering shaft.
It is a further object of the invention to provide an omnidirectional vehicle as stated above, which can minimize the capacity of the motor for driving the steering shaft by preventing the external torque turbulence from being transmitted to the motor for driving the steering shaft.
It is a still further object of the invention to provide an omnidirectional vehicle as stated above, which can reduce the dimensions, weight, costs and energy consumption of the vehicle, reduce the dimensions and weight of the battery, and elongate the time of autonomous traveling by the battery.
According to a first aspect of the invention, there is provided an omnidirectional vehicle comprising: a body; a driving unit fixed to the body and including a steering shaft, a first actuator fixed to the body for driving the steering shaft, a driving wheel including a shaft, and a second actuator fixed to the body for driving the shaft of the driving wheel; a bearing fixed to the body for axially supporting the steering shaft; first power transmitting means for transmitting a power from the first actuator to the steering shaft to drive the steering shaft; a second power transmitting means for transmitting a power from the second actuator to the driving wheel to drive the driving wheel; supporting means positioned below the steering shaft for axially supporting the driving wheel via a bearing to rotate the driving wheel together with the steering shaft around the vertical axis of the body. The driving wheel is positioned at a location spaced apart for a first predetermined distance (d) from a plane including the rotation axis of the steering shaft and extending perpendicular thereto, i.e. parallel to the shaft of the driving wheel, the location being spaced apart for a second predetermined distance (s) from a plane including the rotation axis of the steering shaft to the shaft of the driving wheel to freely rotate the driving wheel around horizontal axes at the orientations. The shaft of the driving wheel and the steering shaft do not cross each other.
Advantageously, the second power transmitting means includes a transmission section A moved by the second actuator around a vertical axis independently of the steering shaft; and a transmission section B linked to the transmission section A and movable around a vertical axis together with the steering shaft. When a reduction gear ratio of the transmission section B is G (deceleration in case G greater than 1) and a radius of the driving wheel is r, the first predetermined distance (d) is expressed by the following equation.
d=r/G
The configuration described above facilitates avoiding the interference between the operations of the actuator for driving the steering shaft and the actuator for driving the shaft of the driving wheels. Since the driving wheel is offset from the center of the body of the vehicle, the power transmission mechanism is simplified, constructed easily and arranged easily.
Advantageously, the supporting means includes a steering shaft connector connected and fixed to the steering shaft, a gear axially supported by the steering shaft connector, and a support link axially supported on the rotation axis of the gear rotatably in a vertical plane for axially supporting the driving wheel; a transmission section b disposed in substitution for the transmission section B, the transmission section b including a gear for driving the driving wheel and being coupled to the gear supported by the steering shaft connector, the transmission section being movable around a horizontal axis together with the steering shaft; and a vibration absorber between the steering shaft and the support link for absorbing vibrations caused while the driving wheel is running on the ground.
Since the above described configuration allows the driving wheel to always touch the ground even when the ground is not flat, sufficient driving force is obtained, the vehicle is stabilized and the running performance of the vehicle is improved especially when the vehicle includes a plurality of the driving wheel.
Advantageously, the vibration absorber includes a spring; and the vehicle further includes vehicle weight measuring means for measuring the total weight of the vehicle including the load thereof or the center of gravity of the vehicle including the load thereof. The vehicle weight measuring means includes a linear position sensor disposed parallel to the spring and having a potentiometer of linear driving type. The linear position sensor measures the deformation of the spring to measure the vertical reactive force exerted to the driving wheel.
By measuring the deformation of the suspension spring for each driving wheel, the total weight or the center of gravity of the vehicle is estimated and the vehicle is further stabilized.
Advantageously, the vehicle includes a rotatable rod inserted through the center of the steering shaft to move up and down in response to the displacement of the vibration absorber rotating in association with the rotation of the steering shaft; and the vehicle weight measuring means for measuring the total weight of the vehicle including the load thereof or the center of gravity of the vehicle including the load. The vehicle weight measuring means includes the linear position sensor disposed in the portion of the vehicle not rotated by the movement of the steering shaft. The linear position sensor includes a potentiometer of linear driving type for measuring the displacement of the rotatable rod to measure the deformation of the vibration absorber. Since it is possible to dispose the sensor for measuring the deformation of the suspension spring on the body of the vehicle, it becomes unnecessary to arrange the wiring on the rotating portions and the reliability of the measuring system is improved.
According to a second aspect of the invention, there is provided a method of controlling an omnidirectional vehicle including a plurality of the driving units described above. The method includes: defining vehicle-based-coordinates, the origin thereof being set at the reference point of the vehicle; and controlling an angular rotating velocity of the first actuator in each of the plurality of the driving units and an angular rotating velocity of the second actuator in each of the plurality of the driving units based on the following equations relating the position data of the steering shaft on each of the plurality of the driving units on the vehicle-based-coordinates and the orientation data of the plurality of driving units on the vehicle-basedcoordinates.
xcfx89mwi=(Gw/r){vvx cos xcex8wi+vvy sin xcex8wi+xcfx89v(xi sin xcex8wixe2x88x92yi cos xcex8wi)}
xcfx89msi=(Gs/s){xe2x88x92vvx sin xcex8wi+vvy cos xcex8wi+xcfx89v(xi cos xcex8wi+yi sin xcex8wi)}
wherein xcfx89mwi is the angular rotating velocity of the actuator for driving the shaft of the driving wheel of the i-th driving unit;
xcfx89msi is the angular rotating velocity of the actuator for driving the steering shaft of the i-th driving unit;
vvx is the velocity of the vehicle along the x-axis;
vvy is the velocity of the vehicle along the y-axis;
xcfx89v is the angular rotating velocity of the vehicle around the reference point;
r is the radius of the driving wheel;
s is the horizontal distance between the steering shaft and the shaft of the driving wheel in the traveling direction of the driving wheel;
xi is the x-axis coordinate on the vehicle-based coordinates for the location of the steering shaft in the i-th driving unit;
yi is the y-axis coordinate on the vehicle-based coordinates for the location of the steering shaft in the i-th driving unit;
xcex8wi is the orientation of the driving wheel in the i-th driving unit on the vehicle-based coordinates;
Gs is the reduction gear ratio of the power transmitting means of the actuator for driving the steering shaft; and
Gw is the reduction gear ratio of the power transmitting means of the actuator for driving the shaft of the driving wheel.
Since each actuator is controlled completely independently by the method described above without considering the operations of the other driving mechanisms, the mechanism and the software of each driving unit may be summarized into a module more easily, and therefore, the driving unit may be designed mare freely.
According to a third aspect of the invention, there is provided an omnidirectional vehicle comprising: a body; a driving set mounted on the body and including a plurality of driving units, each including a steering shaft and a driving wheel having a shaft; a first actuator for driving the steering shafts of the driving units collectively via first power transmitting means including a belt or a chain; a second actuator for driving the driving wheels of the driving units via second power transmitting means; a bearing mounted on the driving set for supporting the body rotatably around the vertical axis of the vehicle; a third actuator mounted on the driving set for rotating the body around the vertical axis of the vehicle; third power transmitting means mounted on the driving set for transmitting the power from the third actuator; and supporting means positioned below the steering shaft for axially supporting the driving wheel via a bearing. The driving wheel is positioned at a location spaced apart for a first predetermined distance (d) from a plane including the rotation axis of the steering shaft and extending perpendicular thereto and parallel to the shaft of the driving wheel, the location being spaced apart for a second predetermined distance (s) from a plane including the rotation axis of the steering shaft to the shaft of the driving wheel to freely rotate the driving wheel around the horizontal axis. The shaft of the driving wheel and the steering shaft do not cross each other.
According to a fourth aspect of the invention, there is provided a method of controlling the omnidirectional vehicle described above. The method comprises: controlling an angular rotating velocity of the first actuator, an angular rotating velocity of the second actuator, and an angular rotating velocity of the third actuator based on the following equations to control the directions and the velocities of the translational movements of the driving units and the body, and the orientation of the body.
xcfx89w=(Gw/r)(vvx cos xcex8w+vvy sin xcex8w)
xcfx89s=(Gs/s)(xe2x88x92vvx sin xcex8w+vvy cos xcex8w)
xcfx89mr=Grxcfx89v
wherein vvx is the velocity of the vehicle along the x-axis;
vvy is the velocity of the vehicle along the y-axis;
xcfx89v is the angular rotating velocity of the vehicle around the reference point;
xcfx89mw is the angular rotating velocity of the actuator for driving the shafts of the driving wheels;
xcfx89ms is the angular rotating velocity of the actuator for driving the steering shafts;
xcfx89mr is the angular rotating velocity of the actuator for driving the turning shaft of the vehicle;
r is the radius of the driving wheel;
s is the horizontal distance between the steering shaft and the driving wheel in the traveling direction of the driving wheel;
xcex8w is the orientation of the driving wheels on the vehicle-based coordinates;
Gs is the reduction gear ratio of the power transmitting means of the actuator for driving the steering shafts;
Gw is the reduction gear ratio of the power transmitting means of the actuator for driving the shafts of the driving wheels; and
Gr is the reduction gear ratio of the power transmitting means of the actuator for driving the turning shaft of the vehicle.
By the configuration and the controlling method described above for driving the driving wheels with one single actuator and the steering shafts with one single actuator, the vehicle is driven with a necessary but minimum number of actuators, and the manufacturing costs of the vehicle are reduced. Since the interference of the translational movement and the rotational movement of the vehicle is avoided, the load of the control system and the dimensions of the actuator for turning the vehicle are reduced.
Advantageously, the foregoing xcex8w is measured by angle measuring means including an angle detector fixed to the body of the vehicle. The shaft of the angle detector is rotated by the first power transmitting means of the first actuator for driving the steering shafts.
Advantageously, the angle measuring means includes a first integrating encoder for detecting the rotation of the shaft of the first actuator; a second integrating encoder for detecting the rotation of the shaft of the third actuator; an absolute encoder for detecting the orientation of the driving wheels with respect to the body of the vehicle with a relatively low resolution; and a differential counter for counting a number of pulses contained in a first pulse train from the first integrating encoder and a number of pulses contained in a second pulse train from the second integrating encoder. The first pulse train indicates a normal rotation or a reverse rotation of the first actuator and is inputted to the positive input of the differential counter, and the second pulse train indicates a normal rotation or a reverse rotation of the second actuator and is inputted to the negative input of the differential counter. The differential counter subtracts the number of pulses contained in the second pulse train from the number of pulses contained in the first pulse train, and outputs the result of the subtraction. The angle measuring means uses the output of the differential counter for the lower place bits and the output of the absolute encoder for the upper place bits. The angle measuring means connects the lower place bits and the upper place bits to obtain the measured relative angle value between the orientations of the vehicle and the driving wheel.
In the above described method, the absolute encoder with a relatively low resolution is mounted on one shaft driven by two actuators, and the value from the absolute encoder is corrected by a hardware, i.e. two integrating encoders mounted on the actuators. Thus, the angle detection can be made with a high precision by cheap sensors without increasing the load of the software.
Advantageously, the relative positional relation between the driving wheel and the steering shaft in the adjacent driving units is changed to opposite to each other to relax the interference caused by external torque turbulence between the driving wheels and the ground where the vehicle is running.
In the configuration as described above, it is possible to eliminate or moderate the external turbulent torque caused from the ground and the steps by the power transmission mechanisms to reduce the adverse effects of the external turbulent torque to the actuators. Thus, the capacities of the actuators an be minimized.
Advantageously, the method further includes: detecting a slip between the driving wheels and the ground based on the output of a sensor disposed on the driving set, the sensor detecting the rotation around the vertical axis of the vehicle and having a gyroscope; and correcting the measured relative angle value between the orientations of the driving wheels and the body of the vehicle based on the detected slip value.
Since the above described method facilitates detecting only the orientation error of the vehicle, the algorithm for detecting the orientation of the vehicle is greatly simplified. Since the above described method facilitates using a rotation measuring system with a low measuring range and a high sensitivity, the measurement and control of the orientation of the vehicle may be conducted with a high precision more than that of the similar conventional system.
Advantageously, the method further includes: detecting the rotation angle around the vertical axis of the vehicle by a sensor disposed on the body of the vehicle and having a gyroscope; and adding the detected rotation angle to the stored data for the orientation of the body of the vehicle to correct stored error data of the orientation of the body of the vehicle.
According to the invention, the interference between the control system and the driving system is avoided, the control system and the driving system are simplified, and the capacities of the actuators and the electric power consumption are reduced. The vehicle according to the invention is a practical holonomic omnidirectional vehicle that can be manufactured at low costs, and exhibit a high reliability with a very precise running capability.